Optimization of natural vanillin production from isoeugenol by pseudomonas putida

In this study, natural vanillin was produced from isoeugenol using Pseudomonas putida HUT 8100 culture and it were investigated optimization ways of conditions which were effective on vanillin yield. Pseudomonas putida culture's growing kinetics were examined primarily for bioconversion. According to viable cell counting results on agar surface, population has reached maximum level in 48 hours and after this moment there has been detected a stationary position in terms of quantitive amounts. Culture was transferred to potassium phosphate buffer medium from GYP (Glucose Yeast Extract Peptone) broth when population reached maximum level in stationary phase at 48th hour. In flask scale bioconversion experience, 3 temperature levels about 24, 28 and 32 oC were tested. It has determined in consequence of experiements; culture showed best vanillin production performance at 28 oC. On next step, it was investigated how vanillin production capacity effected by changing potassium ion concentration and correspondingly changing pH of medium. The most effective production was seen in medium which contains 4.84 g/L K2HPO4 and 16.65 g/L KH2PO4 (with pH 6.30). Bioconversion performance of Pseudomonas putida, an aerobe culture, was also studied in non-aerated and semi-aerated conditions. There was obtained higher bioconversion yield when semi-aerated conditions used. Using obtained results (at 28 oC and 6.30 pH), different isoeugenol amounts added to bioconversion medium in erlen-mayer flasks. After 120 hours for bioconversion, vanillin reached 9.14 g/L in case of 40 % (w/v) isoeugenol was added to medium. Eventually, optimizing of bioconversion parameters which are effective on yield caused a significant increase in vanillin yield. KEY WORDS: Bioconversion, Pseudomonas putida, vanillin, isoeugenol